Wayne Rooney says Manchester United on their guard for visit to Wolves

Wayne Rooney, right, challenges Ronald Zubar of Wolverhampton Wanderers on Manchester United's last league visit to Molineux which ended in a 2-1 defeat in February 2011. Photograph: Nick Potts/PA

Wayne Rooney says Manchester United will be on their guard on Sunday when they visit Wolves, for the Molineux strugglers have a potent record against the league leaders.

United have won two of their past seven top-flight trips, a run that dates back to September 1979.

Last season Wolves were bottom when they entertained United but still managed to inflict their visitors' first defeat of the season, coming from behind to do so. It is a record that demands maximum concentration for all the upheaval Wolves have suffered following the sacking of Mick McCarthy last month.

"Wolves are fighting for their lives after going through a bit of a sticky patch," said Rooney. "I'm sure it's been hard for them to lift themselves, but when you go to the home of a team fighting to survive it's always very difficult – we certainly need to be at our best."

With Manchester City not in action until Wednesday, against Chelsea, United can go four points clear at the top. "It's a massive game for us, so we have to get the three points."